Method and apparatus for installing an insertable hanger shoulder ring in a wellhead

ABSTRACT

A split ring is provided for insertion in a wellhead body to provide a substantial shoulder therein upon which a casing or tubing hanger, or a series of hangers, may be supported. The wellhead body is provided with a groove to receive the ring. The ring is inserted independently of the hangers and several designs of insertion tool are disclosed.

United States Patent Hull et al.

[5 METHOD AND APPARATUS FOR INSTALLING AN INSERTABLE HANGER SHOULDER RING IN A WELLHEAD Inventors:

both of Houston, Tex.

Assignee:

Filed:

Appl. No.:

April 3, 1970 John L. Hull; Charles D. Bridges,

Gray Tool Company, Houston, Tex.

u.s. Cl ..l66/315, 166/208 1m. c1 ..E2lb 23/04, E2lb 43/10 Field of Search ..l66/208, 206, 214, 237, 315,

[56] References Cited UNITED STATES PATENTS Putch 166/208 51 Aug. 15, 1972 3,381,983 5/1968 Hanes ..285/32l 2,394,977 2/ l 946 Boynton 166/1 25 2,877,732 3/1959 Eaton ..285/321 X FOREIGN PATENTS OR APPLICATIONS 668,574 2/1966 Belgium ..285/321 Primary Examiner-Stephen J. Novosad Att0rneyCushman, Darby & Cushman ABSTRACT A split ring is provided for insertion in a wellhead body to provide a substantial shoulder therein upon which a casing or tubing hanger, or a series of hangers, may be supported. The wellhead body is provided with a groove to receive the ring. The ring is inserted independently of the hangers and several designs of insertion tool are disclosed.

5 Claims, 12 Drawing Figures mtmmwcl w 3.684.016 sum 3 0r 5 w a N AWORZ PATENTEDMJG 1 1912 3.684.016

. H x308 m INVENTORS Jaw/v L u z. .z. CI/HKL Es .0. BR/0 GES ATTORNEYS PATENTEDmc 15 1912 SHEET 5 0F 5 Hz/am s? M w W w METHOD AND APPARATUS FOR INSTALLING AN INSERTABLE HANGER SHOULDER RING IN A WELLIIEAD BACKGROUND OF THE INVENTION There are instances where it is impractical or impossible to simply provide an integral, inwardly protruding seat in the bore of a wellhead and to support hangers upon such a seat. When integral inwardly protruding seats cannot be provided there appear to be at least the following choices (the numbers refer to exemplifying U.S. patents).

A. Provide a seat normally stored in a recess in the head which, when needed, is caused to extend into the bore.

1. The seat may be a split or segmented ring or slips a. normally expanded, must be forced inward (Pierce, Jr. U.S. Pat. No. 3,405,956); or b. normally contracted, is forcibly expanded and latched for storage condition (no example at hand) 2. The seat may be the ends of retractable screws (Penick et al. U.S. Pat. No. 2,254,752) (Jackson, Jr. et al. U.S. Pat. No. 3,017,931) (Pierce, Jr. U.S. Pat. No. 3,248,133)

B. Provide a seat normally stored in a recess in the hanger which, when needed, is caused to extend into the bore.

1. The seat may be a split or segmented ring or slips a. normally expanded, must be forced inwardly [and latched] for storage condition (Penick et al. U.S. Pat. No. 2,035,834) (Barker U.S. Pat. No. 2,104,180) (McClintock et al. U.S. Pat. No. 3,097,000) (Pierce, Jr. US' Pat. No. 3,341,227,1ockdwn 48) (Pitts et al. U.S. Pat. No. 3,405,763)

b. normally contracted, is forcibly expanded for C. Provide a separate seat element which is neither i normally stored in the head or the hanger but which is installed after some drilling using a lowering and setting tool (McLaine et al. U.S. Pat. No. 1,536,680) (Crain et al. U.S. Pat. No. 3,265,409).

The present invention relates to equipment and a method of Type C.

For someone who had no experience with oil field realities, it would be easy to conclude that equipment of types A and B would always be preferred over equipment of type C, since the latter requires an extra tool and possibly an extra trip into the well before the casing or tubing string can be run.

Heads such as those cited and having a ring normally stored in a recess within the head (Type A) are subject to malfunction as a result of barites infiltrating into the recess cavity and hardening during drilling operations. Such barites and other foreign matter can prevent a ring from being moved into proper position when desired. Any collection of barites or other foreign matter in the Type C equipment ring recess in the apparatus of the invention can be washed out prior to installation of the ring, thus assuring proper positioning of said ring.

Economics is definitely a consideration in favor of the design of the present invention as compared to those requiring a series of screw-on latch mechanisms. Although the apparatus of the present invention requires a running or setting tool, the tool may be used v subsequently time and again such that its initial cost becomes relatively insignificant over a period of time. The setting tool might also be provided on a rental basis if desired by the customer.

With the use of the hydraulic or mechanical release type setting tools in accordance with certain hereinafter described embodiments of the present invention, an operational advantage may be realized in that manual operation of a screw or latch mechanism at the wellhead is not required. This is particularly desira ble if the wellhead is underwater and would require divers for actuating a screw or latch mechanism.

In some prior Type C equipment, the casing hanger or tubing hanger itself is modified to become the tool for lowering and setting the split shoulder ring.

Carrying the shoulder ring to its proper position in the head with the casing hanger itself is not always practical. Should the casing become stuck before a hanger, carrying the shoulder ring, can be lowered to its proper position in the wellhead, it would become extremely difficult to remove the hangerand, by some other means, install the shoulder ring to provide a seat for a slip type hanger. By installing the ring with a separate setting tool prior to running casing, this potential problem is eliminated. This trouble can and has happened with mudline suspension shoulder ring carrying hangers known to the present inventors.

In one hereinafter described embodiment of the invention, the shoulder ring is triggered by contact from below with set screws or hold down screws run into the head bore after the lowering tool has positioned the ring below the level of the screws. This embodiment and the others to be described possess an advantage over the pawl triggered ring expansion described in the aforementioned U.S. Pat. of Pitts et al. No. 3,405,763 in that they do not require reciprocation of the casing to release or trigger the ring, since the ring is installed prior to running casing. Multiple rings may also be more easily installed in a given head using the hydraulic or mechanical setting tools as described hereinafter.

SUMMARY OF THE INVENTION This invention relates to an insertable split ring for wellheads to provide a substantial shoulder within said wellhead body upon which a casing or tubing hanger, or series of hangers, may be supported. The wellhead body for use with this insertable or snap-in shoulder ring is provided with a mating groove, or series of grooves, to receive the ring.

Several advantages of an insertable, and replaceable, shoulder ring in various wellhead applications are as follows:

1. Allows for placement or replacement of the hanger shoulder within a head at any time prior to running and hanging casing. Integral hanger shoulders are sometimes severely damaged by bits and tool joints during drilling operations, and more frequently are wallowed out by the kelley during drilling, particularly offshore.

2. Provides adequate hanger shoulder or shoulder width to keep bearing stresses within safe ranges when hanging extreme casing loads, while at the same time, allowing maximum size bits to be run. For example, a multi-bowl head for a casing tubing program of 13% X 9% X 7 X 2"/; inches might have a minimum bore of 12% inches in order to pass a 12% inch bit used for drilling hole for the 9% inch casing. The maximum hanger bore for this head is 13% inches since, of course, 13% inch blowout preventers are to be used. The difference in these two bores is 1% inches providing a hanger shoulder of nine-sixteenths inch. This resulting shoulder could, in some cases, be inadequate from a bearing standpoint for supporting the accumulative load of the 9%, 7 and 2 /8 inch casing and tubing strings. Should this shoulder become reduced by kelley wear, bearing stresses could become very critical.

3. May provide adequate hanger shoulder within a multiple-bowl head for independently suspending casing and tubing by using two or more snap-in shoulder rings in the one head. Each ring in this case may provide substantially wide shoulder for each hanger and not interfere with the running of maximum size bits since they would be installed after drilling and prior to running casing.

In (2) above, independent suspension of two strings of casing and one string of tubing on integral hanger shoulders provided in the available space would result in a shoulder of only approximately three-sixteenths inch for each hanger. This, of course, would certainly be inadequate for extreme loads.

4. May provide hanger shoulders in heads where no available space is possible for integral shoulders. For example, a casing tubing program of 16 X 10% X 7 X 2 inches is required, and it is desired that a 13% inch nominal size head and 13% inch preventers be used. In this case, since the minimum bore in the head would conventionally be 12% inches, a hole opening bit would be required to drill sufficient hole for the inch casing string and assure a good cement job. The use of a snap-in hanger shoulder ring, however, would allow the head to have a minimum bore near that of the 13% inch preventers so that a conventional 13% inch bit could be run to drill hole for the 10% inch casing thus eliminating the need for a usually more expensive and less efficient hole opening bit. Here once again, a 13% inch hole could be drilled, the drill pipe and bit pulled, the snap-in hanger shoulder ring installed in the head, and the 10% inch casing string run, hung and cemented safely.

Five variations of acceptable, independent tools for setting split, snap-in shoulder rings in wellhead grooves are shown in the drawings and described hereinafter.

The first includes a cylindrical body unit threaded at its upper end for drill pipe connection, a slidable outer sleeve contained on the body unit by a shoulder and a retainer snap ring, said sleeve having a slot at its lower end containing a slidable block which carries two retainer pins extending from its lower end and through two corresponding holes at the lower end of outer sleeve and at the bottom of slot.

The snap-in shoulder ring is installed on the setting tool by slipping it over the lower end of the tool retracting it inward with a tool such as is used to arm the DJ hanger snap rings of Pitts et al. US. Pat. No. 3,405,763, and slipping it onto the retainer pins extending through the lower end of outer sleeve.

The snap-in shoulder ring may then be installed in a wellhead containing an internal groove prepared to receive the ring, and a series of set screws located-a proper distance above said groove. The setting tool containing the shoulder ring is run into the wellhead bore to a position below the shoulder ring groove and set screws. The set screws are then run inward a predetermined distance or number of turns so as to project into the wellhead bore. The setting tool is then lifted or raised. As the tool is raised, the outer sleeve will contact the set screws and stop while the remaining portion of the tool continues to move forward. The continued upward movement of the tool carries the retainer pin block upward with it by means of the shoulder, and relative to the outer sleeve. This upward movement of the retainer pin block in the slot of the outer sleeve withdraws the retainer pins from their extended position with respect to the lower end of the outer sleeve, thus also withdrawing the pins from the retracted shoulder ring, allowing the shoulder ring to snap outward into its mating groove in the wellhead bore. The set screws are then retracted from their extended position in the wellhead bore, allowing the setting tool outer sleeve passage to be removed from the wellhead bore with tool, leaving the shoulder ring installed in the wellhead groove.

The procedure in accordance with a second-illustrated embodiment also utilizes set screws for actuation, but has certain advantages over the first. It does not require that the tool be pulled up against extended set screws. (It is more difficult to pick up precisely with a drilling rig than it is to slack of This second tool incorporates a threaded outer sleeve to retain the contracted shoulder ring. The outer sleeve contains a series of slots along its outer surface to correspond with the set screws in the head. The tool may be lowered into the head to gently engage the extended set screws and rotated until the slots in the tool outer sleeve align with the set screws, allowing the tool to be lowered further into position. Rotation of the inner main portion of the tool causes the tool body to be moved downward relative to the outer sleeve, causing the shoulder ring to come out from under the restraining outer sleeve, thus expanding outward against the wellhead bore. The set screws may then be retracted and the entire setting tool lowered to push the shoulder ring into its recess in the head bore. the setting tool may then be picked up and removed, leaving the shoulder ring installed in the wellhead.

Three further illustrated setting tools provide means for installing the shoulder ring without having to run in set screws or the like.

One is an hydraulically actuated tool wherein water or mud may be pumped down the drill pipe to actuate a small piston to withdraw two retaining pins from a contracted shoulder ring, allowing the ring to expand against the wellhead bore and be pushed into its corresponding recess in said wellhead bore.

Another is a similar setting tool wherein the piston carrying the retainer pins for the contracted shoulder ring is pulled upward by means of an overshot device fastened to small pipe or tubing and lowered into the hole to engage a fishing neck connected to said retainer pin piston.

A third is similar to the one just mentioned except that the retainer pin piston contains an eye bolt through which a length of soft line may be looped and lowered into the hole with the setting tool.

The principles of the invention will be further hereinafter discussed with reference to the drawings wherein preferred embodiments are shown. The specifics illustrated in the drawings are intended to exemplify, rather than limit, aspects of the invention as defined in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a fragmentary longitudinal sectional view of a wellhead body showing a shoulder ring being run on a first embodiment of the tool;

FIG. 1B is a fragmentary longitudinal sectional view of a wellhead body showing the shoulder ring set in place using the tool of FIG. 1A;

FIG. 1C is a fragmentary elevation view of the tool showing the ring ends held by a retainer;

FIG. 2 is a fragmentary longitudinal sectional yiew of a partly assembled wellhead showing wellhead parts supported from the shoulder ring set in accordance with the principles of the invention;

FIGS. 3A, 3B and 3C are fragmentary longitudinal sectional views of a wellhead body showing progressive steps in the running and setting of the shoulder ring using a second embodiment of the tool;

FIGS. 4A, 4B and 4C are fragmentary longitudinal sectional views of a wellhead body showing progressive steps in the running and setting of the shoulder ring using a third embodiment of the tool;

FIG. 5 is a fragmentary longitudinal sectional view of a wellhead body showing the running of the shoulder ring using a fourth embodiment of the tool; and

FIG. 6 is a fragmentary longitudinal sectional view of a wellhead body showing the running of the shoulder ring using a fifth embodiment of the tool.

DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS The shoulder ring 62 is adapted to be run and set in wellhead bodies of diverse construction, to and including surface, mudline and downhole casing heads, tubing heads, multiple-bowl wellhead bodies both of the kind where several casing and/or tubing hangers rest directly or indirectly upon one another and ultimately upon one or more seats in the head (as in the U.S. Pat. of Pierce, Jr., No. 3,311,168, issued Mar. 28, 1967) and of the kind where several casing and/or tubing hangers rest directly upon individual supports (as in the U.S. Pat. Of Pierce, Jr., No. 3,248,132, issued Apr. 26, 1966, and as in the U.S. Pats. of Stone, No. 3,190,354, issued June 22, 1965 and No. 3,223,168, issued Dec. 14, 1965). In the latter instances two or more of the shoulder rings can be set by identical means, spaced one above the other in the wellhead body. However, it is believed that the principles of the invention can be fully understood with reference to a comparatively uncomplicated wellhead body 12, shown in the drawings.

With reference to FIGS. 1A and 1B, the wellhead body 12 is a generally tubular member adapted'to be connected in a string of conduit, such as well casing,

which, either directly upon the top of the wellhead body 12, or spaced upwardly in the conduit string from the top of the wellhead body 12, includes, during at least a drilling phase of creation of the well, a blowout preventer. A blowout preventer is a tubular element, or a stack of such elements, which contains radially reciprocable or constrictable ram elements adapted to rapidly completely close off the longitudinal bore through the tubular element whether or not other well construction elements such as drill pipe are extending down through the longitudinal bore. Such ram elements may be both manually operable and automatically actuable upon the sensation of a change of pressure conditions within the well or a sensation of incipient movement of certain well elements. One typical mounting of a blowout preventer stack on a wellhead is illustrated in the U.S. Pat. of Crain, No. 3,313,347 of Apr. 11,1967.

The wellhead body 12 illustrated has a generally cylindrical, longitudinal, vertical throughbore 14 provided at at least one level with a circumferential groove 16 which faces radially inwardly and includes bottom and top walls 18, 20 and outer wall 22. Above the level of the groove 16, the head body is provided with at least one and preferably a plurality of angularly spaced radially oriented ports 24 each for receipt of a holddown or set screw 26, having a tapered nose 28.

The ports 24 and screws 26 are of conventional construction. Essentially, outer ends of the screw assemblies which protrude from the exterior of the wellhead body may be manipulated to advance and retract the screws.

The shoulder ring installation tool 30 comprises a tubular portion 32 having an upper end flange 34 provided with means for connecting the tool to a string of drill pipe or the like. In the tool illustrated the flange 34 is provided with an internally threaded box upper end 36.

Externally, the tubular portion 32 includes an upwardly facing circumferential shoulder 38 near its lower end, a circumferential groove 40 near its upper end for receipt of a snap ring 42.

Intermediate these levels the exterior of the tubular portion 32 is shown provided with a circumfercial, upwardly facing shoulder 44. The purpose of the shoulder 44 could be served by providing a shelf of substantially less angular extent, the circumferential extensiveness merely permits easier manufacturing and assembly.

An outer cylindrical sleeve 46 is received over the upper end of the tool body 32 prior to installation of the snap ring 42. This sleeve is axially shorter than the distance between the snap ring 42 and shoulder 38 and is retained on the tool body by these elements for sliding movement limited by contact with them.

The outer sleeve 46, at one angularly brief location, is provided with a notch 50 intermediate its upper and lower extent which is shown extending all of the way, radially, through the outer sleeve. A retainer pin block 52 is received in the notch; it is much shorter than the notch is high and rests on the shoulder surface 44. Two retainer pins 54, which are vertical, parallel to one another and spaced angularly of one another a short distance, have their upper ends securely mounted in the retainer pin block 52 at 56. In FIGS. 1A and 1C these pins are shown extending down through two corresponding openings 58 through the outer sleeve 46 lip 60 below the notch 50 and protruding therebelow.

The snap-in shoulder ring 62 is a forcibly, elastically contractile, self expansible split C-shaped ring 10 which angularly extends through nearly a complete circle, so that its ends lie near one another. Near each of these ends the ring is provided with an axially oriented socket 64. The snap-in shoulder ring 62 is installed on the tool by slipping it over the lower end of the tool, radially retracting the ring using the same kind of tool as used to arm the DJ hanger snap rings of Pitts et al., U.S. Pat. No. 3,405,763, and slipping its two sockets 64 over the protruding lower ends of the two retainer pins 54.

After drilling the well to the point where a string of casing or tubing is to be hung in the well from a point in the wellhead body 12, the tool 30 with the split ring 62 contracted thereon is run into the wellhead bore to a position below the shoulder ring groove 16 and set screws 26. The set screws are then run inward a predetermined distance or number of turns (see FIG. 1B) so as to project into the wellhead bore. The setting tool 30 is then lifted or raised. As the tool is raised, the outer sleeve 46 contacts the protruding set screws 26 and is thus stopped from further upward movement. However, the remainder of the tool continues to move upward carrying the retainer pin block 52 up on the shoulder 44. This movement relative to the outer sleeve 46 results in the retainer pins 54 being pulled from the ring sockets 64. This allows the shoulder ring 62 to snap outward into its mating groove 16 in the wellhead base. (note that relative vertical distances between the parts just described are such that, as the pins withdraw from the sockets the ring 62 is radially adjacent the groove 16.)

The set screws are then retracted so they no longer protrude into the wellhead bore, allowing the setting tool to be removed from the well, leaving behind only the emplaced shoulder ring 62 which is received in the groove in contact with the top, bottom and outer walls thereof and protrudes so substantially into the wellhead bore as to provide a strong shoulder 70 for receiving and supporting a casing hanger or the like.

In FIG. 2 a typical installation is depicted, many parts being labeled by name for imparting a rapid understanding of what is depicted.

With reference to FIGS. 3A, 3B and BC, the mechanical setting tool 30A utilizes set screws for actuation but has certain advantages over the tool 30 of FIGS. lA-lC. In particular, it does not require that the tool be pulled up against extended set screws, and as is known, it is more difficult to pick up precisely with a drilling rig that it is to slack off.

The tool 30A incorporates a threaded outer sleeve 46A to retain the contracted shoulder ring 62. The outer sleeve contains a series of slots 80 along its outer surface to correspond in angular location with the set screws in the head. The slots open radially outwardly, extend vertically and run off the lower, radially outer corner of the exterior of the outer sleeve 46A. The tool may be lowered into the head to gently engage the extended set screws and rotated until the slots in the tool outer sleeve align with the set screws, allowing the tool to be lowered further into the position shown in FIG. 3A. Rotation of the inner main portion 32A of the tool by rotation of the string 82 to the lower end of which the tool body is secured causes the body to be moved downward relative to the outer sleeve. Thus the shoulder ring is caused to become out from under the restraining outer sleeve, whereupon it expands outward against the wellhead bore as shown in FIG. 3B. The set screws may then be retracted and the entire setting tool lowered to push the shoulder ring into its recess in the head bore as shown in FIG. 3C. The setting tool may then be picked up and removed, leaving the shoulder ring installed in the wellhead.

The setting tools 30B, 30C and 30D shown in FIGS. 4A, 4B, 4C; 5 and 6 provide a means of installing the shoulder ring without actuating set screws or the like.

The tool 308 of FIGS. 4A, 4B and 4C is a hydraulically actuated one wherein water or mud may be pumpeddown the drill pipe 82 to actuate via conduit 88 and cylinder 90 a small piston 86 to withdraw the two retaining pins 54 secured in and depending from the piston into the ring sockets 64, FIG. 4A, from the contracted shoulder ring 62, allowing the ring to expand against the wellhead bore (FIG. 4B) and be pushed into its corresponding recess in said wellhead bore (FIG. 4C) whereupon the tool may be withdrawn from the well.

The tool 30C of FIG. 5 is a similar setting tool .wherein the piston 86 carrying the retainer pins 54 for the contracted shoulder ring is pulled upward by means of an overshot device 92 fastened to small pipe or tubing 94 and lowered into the hole to engage a fishing neck 96 connected to said retainer pin piston 86 and projecting axially upwardly therefrom. Then the expanded ring may be pushed into the wellhead recess and the tool may be withdrawn from the well. I

The tool 30D of FIG. 6 is similar to that of FIG. 30C except that the retainer pin piston 86 contains an eye bolt 98 through which a length of soft line 100 may be looped and lowered into the hole with the setting tool. The piston is moved by pulling on the line 100. Then the expanded ring may be pushed into the wellhead recess and the tool may be withdrawn from the well.

It should now be apparent that the insertable hanger shoulder ring for wellheads and setting tool for same as described herein above possess each of the attributes set forth in the specification under the heading Summary of the Invention hereinbefore. Because the insertable hanger shoulder ring for wellheads and setting tool for same of the invention can be modified to some extent without departing from the principles of the invention as they have been outlined and explained in this specification, the present invention should be understood as encompassing all such modifications as are within the spirit and scope of the following claims.

What is claimed is:

l. A method for installing a split, elastically forcibly contractile, self-expansible shoulder ring in a circumferential groove in a wellhead body longitudinal bore, comprising:

forcibly contracting the ring on a setting tool;

pinning the ring in a contracted condition to maintain the ring in said contracted condition; lowering the tool carrying said ring into the wellhead body through-bore to proximity with the circumferential groove;

unpinning the ring and allowing it to self-expand into contact with the wellhead body through-bore;

adjusting the level of the unpinned ring to the level of the groove whereby said ring self-expands into said groove; and

withdrawing said setting tool from the well;

the ring having a socket formed axially therein near each split end thereof, the step of pinning the ring in a contracted condition comprising inserting a pin into each socket and retaining the pins a fixed distance apart; and

the step of unpinning the ring comprising pulling the pins from the sockets.

2. The method of claim 1 wherein the pins are connected to a projection and said step of pulling comprises pulling said projection.

3. The method of claim 1 wherein the pins are connected to a projection and said step of pulling comprises running a screw radially into the wellhead body longitudinal bore above the projection, raising the tool until the projection becomes snagged on the screw, then raising the tool sufficiently further to pull the pins from the ring.

4. Apparatus for installing a split, elastically forcibly contractile, self-expansible shoulder ring in a circumferential groove in a wellhead body longitudinal bore, so that a hanger may thereafter be run into the well and supported on said shoulder ring, said apparatus comprising:

a setting tool having a tubular body;

a split, elastically forcibly contractile, self-expansible shoulder ring forcibly contracted into substantially circumferential engagement with the exterior of said tubular body; and

means on said setting tool for pinning said ring in contracted condition on said tubular body;

said pinning means comprising means defining two sockets each being formed axially in the ring near each split end thereof; two parallel pins; retainer block means mounting said pins laterally adjacent one another a fixed distance apart; said pins being received in said sockets;

an annular outer sleeve circwmferentially, axially slidably received on said tubular body above and in axial alignment with the contracted shoulder ring for contact therewith; lower stop shoulder means provided on said tubular body; upper stop shoulder means provided on said tubular body;

notch means formed. radially through said annular outer sleeve; surface means on said retainer block means and on said tubular body, between said upper and lower stop shoulder means for ensuring conjoint upward movement of said retainer block means and said tubular body;

the upper extent of said outer sleeve normally being disposed near said upper stop shoulder means;

the lower extent of said contracted shoulder ring normally being disposed spaced above said lower stop shoulder means;

whereby when a projection is run into the bore of the wellhead body above said annular outer sleeve and said tool is raised, the outer sleeve can strike the projection and cease moving upwardly, whereupon further upward movement of the tool will carry the retainer block upwardly relative to the contracted ring, and the shouldering down toward the lower stop shoulder and thus pull the pins from the ring sockets and allow the rin to self-expand 5. The apparatus of claim 4 w erein the axial distance between the lower stop shoulder and the upper extent of the outer sleeve is equal to the axial distance between the lower extent of the circumferential groove in the throughbore of the wellhead body and the projection run into said bore, whereby said shoulder ring is automatically positioned radially adjacent the circumferential groove when the shoulder ring becomes free to self-expand. 

1. A method for installing a split, elastically forcibly contractile, self-expansible shoulder ring in a circumferential groove in a wellhead body longitudinal bore, comprising: forcibly contracting the ring on a setting tool; pinning the ring in a contracted condition to maintain the ring in said contracted condition; lowering the tool carrying said ring into the wellhead body through-bore to proximity with the circumferential groove; unpinning the ring and allowing it to self-expand into contact with the wellhead body through-bore; adjusting the level of the unpinned ring to the level of the groove whereby said ring self-expands into said groove; and withdrawing said setting tool from the wEll; the ring having a socket formed axially therein near each split end thereof, the step of pinning the ring in a contracted condition comprising inserting a pin into each socket and retaining the pins a fixed distance apart; and the step of unpinning the ring comprising pulling the pins from the sockets.
 2. The method of claim 1 wherein the pins are connected to a projection and said step of pulling comprises pulling said projection.
 3. The method of claim 1 wherein the pins are connected to a projection and said step of pulling comprises running a screw radially into the wellhead body longitudinal bore above the projection, raising the tool until the projection becomes snagged on the screw, then raising the tool sufficiently further to pull the pins from the ring.
 4. Apparatus for installing a split, elastically forcibly contractile, self-expansible shoulder ring in a circumferential groove in a wellhead body longitudinal bore, so that a hanger may thereafter be run into the well and supported on said shoulder ring, said apparatus comprising: a setting tool having a tubular body; a split, elastically forcibly contractile, self-expansible shoulder ring forcibly contracted into substantially circumferential engagement with the exterior of said tubular body; and means on said setting tool for pinning said ring in contracted condition on said tubular body; said pinning means comprising means defining two sockets each being formed axially in the ring near each split end thereof; two parallel pins; retainer block means mounting said pins laterally adjacent one another a fixed distance apart; said pins being received in said sockets; an annular outer sleeve circumferentially, axially slidably received on said tubular body above and in axial alignment with the contracted shoulder ring for contact therewith; lower stop shoulder means provided on said tubular body; upper stop shoulder means provided on said tubular body; notch means formed radially through said annular outer sleeve; surface means on said retainer block means and on said tubular body, between said upper and lower stop shoulder means for ensuring conjoint upward movement of said retainer block means and said tubular body; the upper extent of said outer sleeve normally being disposed near said upper stop shoulder means; the lower extent of said contracted shoulder ring normally being disposed spaced above said lower stop shoulder means; whereby when a projection is run into the bore of the wellhead body above said annular outer sleeve and said tool is raised, the outer sleeve can strike the projection and cease moving upwardly, whereupon further upward movement of the tool will carry the retainer block upwardly relative to the contracted ring, and the shouldering down toward the lower stop shoulder and thus pull the pins from the ring sockets and allow the ring to self-expand.
 5. The apparatus of claim 4 wherein the axial distance between the lower stop shoulder and the upper extent of the outer sleeve is equal to the axial distance between the lower extent of the circumferential groove in the throughbore of the wellhead body and the projection run into said bore, whereby said shoulder ring is automatically positioned radially adjacent the circumferential groove when the shoulder ring becomes free to self-expand. 